Bond worked over weakling — not the first (7)
I believe the answer is:
linkage
'bond' is the definition.
(I've seen this in another clue)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for linkage that I've seen before include "where the join is" , "System of connections" , "Connection, coupling" , "Part of mechanism" , "Leaking (anag)" .)